JPS6360080B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for purifying a raw material gas for synthesis containing carbon monoxide and at least oxygen as an impurity. [Prior art] As a typical gas containing carbon monoxide,
Examples include converter gas obtained from converters in steel plants, electric furnace gas obtained from electric furnaces, and generator gas obtained by gasifying coke. Some of these gases contain 70
Some contain more than % carbon monoxide,
Usually, most of it is consumed as fuel, but recently, attention has been focused on carbon monoxide, and attempts have been made to use it as a raw material for organic synthesis. However, the gases obtained from various furnaces contain impurities. For example, nitrogen, hydrogen, carbon dioxide,
Contains oxygen, hydrogen sulfide, water, methane, etc. Among these components, carbon dioxide, oxygen, hydrogen sulfide,
If water or methane is present, it will affect the organic synthesis catalyst and inhibit the carbon monoxide reaction, making it impossible to expect a sufficient synthesis reaction. For example, the presence of oxygen (O ₂ ) has a significant negative effect on the synthesis reaction of formic acid. Therefore, it was necessary to perform some kind of pretreatment to sufficiently remove these impurities. Among these impurities, carbon dioxide, hydrogen sulfide, water, etc., which have different adsorption properties from carbon monoxide due to their molecular shape, etc., can be extracted using the well-known pressure swing method (PSA method) or temperature swing method (TSA method). can be removed using an adsorbent (“pressure swing cycle system”)
Kenichiro Suzuki and Hiroshi Kitagawa: Published by Kodansha in 1983),
(“Practical Design of Dehumidification for Air Conditioning Engineers” by Suzuki and Oya: published by Kyoritsu Publishing), (“Basics and Design of Adsorption” by Kenichiro Suzuki and Hiroshi Kitagawa: published by Maki Shoten). On the other hand, as a method for removing oxygen, first, by bringing it into contact with a copper catalyst, oxygen and carbon monoxide are reacted to form carbon dioxide, and then the
There is a method of adsorbing and removing carbon dioxide using an adsorbent using the PSA method or the TSA method. Since hydrogen sulfide, water, etc. are also adsorbed in the process, all harmful impurities should be removed simply by the process described above. [Problems to be Solved by the Invention] However, sulfur compounds such as hydrogen sulfide poison the catalysts mentioned above. The raw material gas often contains sulfur compounds, and if the above step is carried out as is, most of the oxygen will remain unreacted in the step, leading to the step. However, while adsorption-based separation removes most of the impurities that are harmful to organic synthesis, most of the impurities remain in the final product, carbon monoxide gas, because the adsorptivity of oxygen is similar to that of carbon monoxide. . Therefore, a raw material gas containing some impurities requires an additional step to remove impurities before the above steps. That is, sulfur compounds such as hydrogen sulfide are removed in advance using the PSA method, etc.
After that, the above steps must be carried out mainly to remove oxygen gas by oxidizing and adsorbing it. In this way, at least three steps are required to completely remove impurities from the carbon monoxide raw material gas, which is disadvantageous in terms of equipment and energy, which increases costs and impedes its use. was. [Objective of the present invention] The present invention was achieved as a result of various studies on a carbon monoxide purification method that solved the above-mentioned problems in carbon monoxide recovery and separation. The objective is to provide a method for purifying a substance into a state suitable for synthesis in basically two steps. [Means for Solving the Problems] That is, the gist of the present invention is to provide a binary composition in which a raw material gas for synthesis containing carbon monoxide and impurities is combined with partially reduced copper oxide and zinc oxide. A first step in which oxygen and carbon monoxide in impurities are reacted and converted into carbon dioxide by contacting with a system catalyst, and the raw material gas that has passed through the first step is heated under pressure with activated carbon or the activated carbon. A method for purifying carbon monoxide gas for synthesis, comprising a second step of adsorbing and removing impurities by passing the gas through an adsorption tower filled with an adsorbent made of a composition of a mixture of zeolite and/or activated alumina. It is in. To explain the present invention in more detail, the raw material gas for synthesis containing carbon monoxide (hereinafter also referred to as "CO") and impurities to which the present invention is applied is, for example, a converter gas generated from a converter in a steel mill. Gas, electric furnace gas obtained from electric furnaces, generating furnace gas obtained by gasifying coke, etc., mainly CO, nitrogen (hereinafter also referred to as "N ₂ "), and a small amount of oxygen (hereinafter "O ₂ ").
), carbon dioxide (hereinafter also referred to as ``CO <sub>2</sub> ''), hydrocarbons such as methane (hereinafter referred to as ``CH ₄ etc.'')
Examples include mixed gases containing water vapor (hereinafter also referred to as "H ₂ O"), sulfur compounds such as hydrogen sulfide (hereinafter also referred to as "H ₂ S, etc."), and the like. In the present invention, the raw material gas for synthesis as described above is brought into contact with a special binary composition catalyst for oxygen removal which is unaffected by impurities, and gases other than CO contained in the gas are removed even in the presence of impurities. Among the components, there is a first step in which O ₂ is converted to CO ₂ , and the raw material gas that has passed through the first step is led to an adsorption tower filled with an adsorbent, and the PSA method is applied to convert CO ₂ as well as H ₂ O, H It is characterized by comprising a second step in which impurities that interfere with synthesis, such as ₂ S and CH ₄ , are adsorbed onto an adsorbent and purified to properties suitable for synthesis. <About the first step> In the method of the present invention, as the O ₂ removal catalyst contacted in the first step of converting O ₂ in the raw material gas to CO ₂ , copper oxide (CuO) whose substrate is partially reduced and zinc oxide (ZnO ) is a binary composition catalyst consisting of
Its composition ratio is CuO: 10 to 40% by weight, preferably
20-40% by weight, ZnO: 90-60% by weight preferably 80
60% by weight, and 4 to 10% by weight of a binder such as graphite is added thereto, and the mixture is molded into a cylindrical shape with a diameter and height of about 3 m/m, respectively. This catalyst is prepared by various known methods. For example, an alkali is added to a mixed solution of inorganic acid salts such as copper and zinc nitrates to adjust the pH, coprecipitate copper and zinc hydroxides, and the precipitated hydroxides are thermally decomposed to form oxides. This method is then molded and partially reduced by contact treatment with a reducing gas containing a small amount of H ₂ gas or CO gas in an inert gas such as N ₂ gas; a mixed solution of copper and zinc nitrates is Support: For example, a reducing gas that is prepared by soaking a support such as alumina, thermally decomposing it, making it into an oxide, and then molding it into an inert gas such as N ₂ gas with a small amount of H ₂ gas or CO gas present. A method in which an inorganic binder such as graphite is added to a mixture of organic acid salts such as copper and zinc acetate, kneaded and molded, and then thermally decomposed to form an oxide. It is prepared by a method such as contact treatment with a reducing gas in which a small amount of H ₂ gas or CO gas is present in an inert gas as described above. The purpose of the partial reduction treatment in preparing the above catalyst is to increase the catalytic activity. In addition, in the first step of the method of the present invention, this partial reduction treatment is
It can also be carried out by filling a catalyst-packed column with a binary composition catalyst consisting of a combination of CuO and ZnO, and then directly passing a reducing gas through the column. This catalyst contains the above-mentioned impurities, namely CO ₂ , H ₂ S,
Catalytic activity is not lost due to impurities such as H ₂ O, CH ₄ , H ₂ and N ₂ . Therefore, O ₂ can be converted to CO ₂ even in the presence of such impurities. The first step of the method of the present invention is to react a small amount of O ₂ present in the raw material gas containing harmful impurities with CO to generate CO ₂
It changes the This reaction between O ₂ and CO is an exothermic reaction, which maintains a constant temperature due to its own heat of combustion, and does not require or require a small external heat source. The O ₂ removal reaction is sufficiently completed at a temperature maintained in the catalyst-packed column under an atmosphere of room temperature to 230°C. Additionally, the reaction between O ₂ and CO proceeds both under normal pressure and under elevated pressure.
There is an advantage that the heat of compression generated during pressure increase can be used, and in the second step described later, which is performed after the first step, it is necessary to pressurize the raw material gas into the adsorption tower under increased pressure. It is preferable to provide a step of previously pressurizing the raw material gas to 4 to 9 atmospheres before the first step. In addition, the space velocity of the gas to be treated whose main component is CO to the catalyst-packed tower is 500 to 600,000 hr ^-1
Existing oxygen can be completely removed by using <Regarding the second step> After the first step, the gas to be treated containing CO _{2 generated by the reaction of a small amount of O 2} contained therein with CO ₂ coexists with CO ₂ , H ₂ O, This leads to the second step of adsorbing and separating gas components such as CH ₄ and H ₂ S that are obstacles to organic synthesis reactions. Purification of the raw material gas in the second step is performed using, for example, the above CO ₂
This is carried out by alternately using a plurality of adsorption towers filled with adsorbents that selectively adsorb the following gas components. That is, the raw material gas is input at room temperature at a pressure of, for example, 4 to 9 atmospheres maintained in the first step, and the gas components below CO ₂ are adsorbed and removed. Although O ₂ is not a target for removal in the second step, since it has already been removed in the first step, it will not remain in the final purified product. Note that if the pressure increasing step is not performed before the first step, it is necessary to provide the pressure increasing step between the second step and the first step. Next, the adsorbed gas components below CO ₂ are purged from the adsorption tower by reducing the pressure in the adsorption tower, and then the already purified gas to be treated is passed back through the adsorption tower to wash the adsorbent. Hereinafter, the so-called PSA system, which is operated cyclically by pipes connecting adsorption towers, switching valves disposed therein, and a control device, will be applied. Activated carbon can be used as the adsorbent packed in the adsorption tower, but among them, 14 to 30 Å
Activated carbon having _a most frequent pore size of Furthermore, a composition in which activated carbon having such a pore size is mixed with zeolite and/or activated alumina can also be used. FIG. 1 is a flow diagram of the above-mentioned PSA method as the second step, and shows an example in which the adsorption tower is of a two-column type. In the figure, F ₁ to ₄ are flowmeters, V ₁ to ₁₀ are switching valves, 1A, 1
B is an adsorption tower, 2a and 2b are adsorbents, 3 is a tank for the purified gas to be treated, 4 is an acid pipe for introducing the gas to be treated after the first step, 5 is a pipe for discharging the purified gas to be treated, Reference numeral 6 designates a purified gas pipe for cleaning, 7 a pipe for passing the gas purified in the adsorption towers 1A and 1B to the gas tank 3, and 8 a gas purge pipe. Next, to describe an example of a purification operation by adsorption separation, with all switching valves other than V ₁ and V ₇ closed, raw material gas is pressurized into the adsorption tower 1A from the raw gas pipe 4, and the CO ₂ or less is The gas component is adsorbent 2a
The purified raw material gas is adsorbed to V ₇ , pipe 7
The purified gas is stored in tanks. On the other hand, the gas components below CO ₂ adsorbed on the adsorbent 2b in the adsorption tower 1B are controlled by switching valves V ₈ , V ₆ , and V ₂ closed, and V ₄ opened.
The pressure inside the tower is reduced, and the gas is discharged to the outside of the system via the gas purge pipe 8. After that, V ₉ , V ₆ , and V ₄ are opened, and V ₂ is closed.
The gas in the purified gas tank 3 is passed back through the pipe 6 to the adsorption tower 1B to clean the impurity agent 2b, and the cleaning gas is discharged to the outside of the system via the gas purge pipe 8. When the cleaning is completed, V ₄ is closed, and the purified gas in the purified gas tank 3 is subsequently introduced back to pressurize the adsorption tower 1B. When pressurization is completed, V ₂ and V ₈ are opened, and V ₆ is closed, and the raw material gas is injected from the raw material gas introduction pipe 4, and the following steps are performed.
Purification of the raw material gas by adsorption, purge of adsorbed gas components under reduced pressure, washing and pressurization of the adsorbent with the purified gas, and pressurization of the raw material gas are repeated. In addition, by the above adsorption operation, the gas components below CO ₂ adsorbed on the adsorbent 2a of the adsorption tower 1A are separated by V ₇ , V ₅ , V ₁ , V ₄ closed, V ₃ opened, and the pressure inside the tower reduced. It is discharged to the outside of the system via the gas purge pipe 8. Thereafter, as in the case of the adsorption tower 1B, the purified raw material gas in the purified gas tank 3 is passed back to the adsorption tower 1A in a pressurized state, the adsorbent 1a is washed and pressurized, and the raw material gas is pressurized by switching the switching valve. , the purification is repeated. These operations, such as opening and closing of the switching valve, are performed by a conventional control device. [Operation] In the first step, a binary composition catalyst combining partially reduced copper oxide and zinc oxide reacts oxygen with carbon monoxide even in the presence of impurities (especially sulfur compounds) to produce carbon dioxide. It is converted into carbon. In the second step, impurities harmful to organic synthesis, including carbon dioxide, are removed using the PSA method. Therefore, carbon monoxide raw material gas from which impurities harmful to organic synthesis have been removed can be obtained basically in two steps. [Effects of the Invention] As described above, the present invention includes a first step in which carbon monoxide raw material gas for synthesis is brought into contact with a binary composition catalyst for oxygen removal to convert it into O ₂ and CO ₂ contained therein. The second step is to adsorb and remove components that may be a hindrance to the organic synthesis reaction by applying the known PSA method.
Guides the process. By using the above-mentioned special catalyst that is highly resistant to impurities in this first step, the raw material gas can be directly processed in the first step without having to undergo a pretreatment step to remove impurities. Impurities are originally secondary
Since it can be removed in the process, the entire process can be performed in two steps, the first step and the second step. Therefore, carbon monoxide raw material gas from which impurities harmful to organic synthesis are sufficiently removed can be obtained using relatively small equipment. Furthermore, it saves energy and is extremely advantageous in terms of cost. [Examples] Next, the present invention will be described with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Note that the first to fourth embodiments are the first to fourth embodiments.
This is an example of the process. Example 1 80wt% CuO-20wt% prepared by coprecipitation method
N ₂ :
A reducing gas (100 c.c./min) consisting of 99.0 vol% and CO: 1.0 vol% was passed through the catalyst at a temperature of 170°C.
Partial reduction was carried out at a pressure of 1 Kg/cm ² G. After this, the first
The composition of the process is CO: 84.5vol%, _N2 : 15.0vol
%, O ₂ : 0.5 vol%, a raw material gas mainly composed of CO was passed through the catalyst phase at a pressure of 1 Kg/cm ² G and a space velocity of 50,000 hr ^-1 under the temperature conditions of the catalyst phase shown in Figure 2. I let it happen. The relationship between the reaction temperature of the catalyst layer and the O ₂ removal rate at this time is shown in FIG. As comparative examples, cases in which a partially reduced CuO catalyst alone is used and a case in which a partially reduced ZnO catalyst alone is used are also described. However, since the ZnO catalyst alone has extremely low activity, the space velocity was 1000 hr ^-1 . Incidentally, the CuO-ZnO catalyst used in this example was prepared as follows. That is, the pH of a mixed solution of copper nitrate and zinc nitrate is adjusted with aqueous ammonia, coprecipitated as copper hydroxide and zinc hydroxide, filtered, dried, and then thermally decomposed in the atmosphere at about 400°C to produce an oxide powder. were mixed and molded. As is clear from the results shown in Figure 2, the method of the present invention using a partially reduced CuO-ZnO binary composition catalyst can easily convert CO to a main component at a low temperature of about 100°C.
It can be seen that O ₂ can be removed from O ₂ -containing gas.
In each case, when the O ₂ concentration in the reaction tube outlet gas was actually measured using a trace oxygen analyzer manufactured by Teledyne, it was confirmed that O ₂ was almost completely removed below the detection limit (0.5 ppm). . At this concentration, there is no problem in organic synthesis using carbon monoxide. Example 2 A reaction tube similar to that in Example 1 was filled with a CuO-ZnO binary composition catalyst prepared in the same manner as in Example 1, and a reducing gas was passed therethrough for partial reduction, and then the catalyst layer temperature was raised to 180°C. ℃ and brought into contact with a test gas containing CO as a main component similar to that in Example 1 under the space velocity and pressure conditions shown in Table 1 below to measure the O ₂ removal rate. The results are shown in the same table. As is clear from this result, it can be seen that the O ₂ removal rate does not decrease even if the space velocity is increased.

[Table] Example 3 A reaction tube similar to that in Example 1 was filled with a CuO-ZnO binary composition catalyst prepared in the same manner as in Example 1, and a reducing gas was passed through it for partial reduction. Keep the layer temperature at 180℃, CO: 84.5vol%,
A test gas consisting of N ₂ : 15.0 vol%, O ₂ : 0.5 vol%, H ₂ S: 1 ppm was heated at normal pressure and at a space velocity of 10000 hr ^-1.
The O ₂ removal rate was measured to see if there was a decrease in activity. The results are shown in FIG. As a comparative example, the results obtained when a partially reduced CuO catalyst alone was used are also shown. As is clear from the results in Figure 3, the method of the present invention using a partially reduced CuO-ZnO binary composition catalyst shows no decrease in O ₂ removal rate even after 3000 hours of use, and has excellent sulfur resistance. It can be seen that the activity is sufficiently maintained. In contrast, CuO in the comparative example
A single catalyst loses its activity relatively early and the O ₂ removal rate decreases. Therefore, in this example, it is not necessary to remove the sulfur compound before the first step. Example 4 The same reaction tubes as in Example 1 were filled with CuO-ZnO binary composition catalysts prepared by changing CuO and ZnO in various ratios, and after partial reduction by passing reducing gas, the medium was removed. The layer temperature was maintained at 100°C, and the same test gas as in Example 1 was heated at normal pressure and space velocity at 50000 hr ^-1.
The relationship between O ₂ removal rate and catalyst composition was examined. The results are shown in FIG. As is clear from this result, in the method of the present invention, when the catalyst composition is CuO: 20 to 40% by weight and ZnO: 80 to 60% by weight, O ₂
It can be seen that the removal efficiency is the most significant. Example 5 The first step is carried out in the same manner as in Example 1. That is, 80wt% ZnO prepared by coprecipitation method - 20wt
N ₂ :
A cyclic gas consisting of 99.0vol% and CO: 1.0vol%
Conducting at a rate of 100c.c./min, the catalyst was heated to a temperature of 170℃.
Partial reduction was carried out at a temperature of 1 Kg/cm 2 G and a pressure of 1 Kg/cm ² G. Next, as the first step, the composition is CO: 84.5vol%, _N2 :
A raw material gas for synthesis mainly composed of CO, consisting of 15.0 vol% and O ₂ : 0.5 vol%, was heated at a pressure of 9 Kg/cm ² G and a space velocity of 50,000 hr ^-1 to bring the temperature of the catalyst phase to approximately 100°C. I held it and let it pass. As a result, the composition is CO:
A gas to be treated consisting of 83.9 vol%, _N2 : 15.1 vol%, and _CO2 : 1.0 vol% was obtained, and _O2 was completely removed. The CuO-ZnO catalyst used in this example was prepared by adjusting the pH of a mixed solution of copper nitrate and zinc nitrate with aqueous ammonia, and co-precipitating it as copper hydroxide and zinc hydroxide.
After filtration and drying, the oxide powder was thermally decomposed in the air at about 400°C, and the resulting oxide powder was mixed and molded. Next, as a second step, O ₂ is not included. C.O.
The above-mentioned gas to be treated consisting of N ₂ and CO ₂ is
As shown in the figure, a two-column type PSA device is used, and the adsorption tower (34 m/mφ x 300 m/m) is filled with 150 c.c. of activated carbon having a most frequent pore diameter of 17 Å.
It was conducted under a pressure of cm ² G at SV 500 hr ⁻¹ to adsorb CO ₂ and purify the gas to be treated. The CO ₂ content in the purified gas to be treated was only 3 ppm, and the CO ₂ generated in the first O ₂ removal step could be almost completely removed. Note that during regeneration, the pressure was reduced to atmospheric pressure, and then backwashing was performed with purified gas to be treated. Example 6 O ₂ removed through the first step, the composition is CO:
A gas to be treated containing 70.9 vol%, N ₂ : 13.1 vol%, and CO ₂ : 16.0 vol% was prepared by using the same two-column apparatus as shown in FIG. 1 as in Example 5, and filling the adsorption column with the same activated carbon. Then, CO ₂ was adsorbed and removed under the same conditions as in Example 5. The composition of the resulting purified gas is
CO: 81.7vol%, _N2 : 18.3vol% residual CO ₂ min is
The amount was only 6 ppm, and very effective adsorption and removal of CO ₂ was achieved. Example 7 After the first step, O ₂ was removed, and the composition was CO:
A gas to be treated containing 75.6 vol%, N ₂ : 4.4 vol%, and CO ₂ : 20.0 vol% was prepared by using a two-column apparatus as shown in Figure 1 as in Example 5, and filling the adsorption column with the same activated carbon. Then, CO ₂ was adsorbed and removed under the same conditions as in Example 5. The composition of the resulting purified gas is
CO: 92.1vol%, _N2 : 7.9vol%, residual CO ₂ minutes is
The amount was only 10 ppm, and very effective adsorption and removal of CO ₂ was achieved. In each of the above Examples, activated carbon or a combination of activated carbon and activated alumina was used as the adsorbent, but similar adsorption effects were obtained by combining activated carbon with zeolite. Example 8 In the gas treatment equipment shown in the flow of Fig. 5, the second
Experiments were conducted using the actual gases shown in the table. In this gas treatment device, along the gas flow path 10,
From upstream, a deoxidizing tower 11, a cooler (water-cooled) 12, two adsorption towers 13, 14, A tower and B tower installed in parallel,
A surge tank 15 and a product tank 16 are provided. Between the cooler 12 and the adsorption towers 13 and 14, there is an electric valve A that is opened and closed by a sequencer.
-1, A-2, B-1, C-1, C-2, G-1
and a manual valve M-1 are installed, and the adsorption towers 13, 14
Between the surge tank 15 and the product tank 16, there are electrically operated valves D-1, D-2, E-1, E-2, F-1, F- which are opened and closed by a sequencer.
2, G-1, manual valve M-2, M-3 and check valve S
-1 and S-2 are arranged. The opening and closing operations of the electric valves A-1 to G-1 by the sequencer are performed as shown in FIG. The hatched portions indicate the closed state of the valve, and the other portions indicate the open state. At this time, A tower 13, B tower 14
are adsorption, equilibrium, depressurization, purge, cleaning, and
Repeat the equilibration/boosting process. The pressure change at this time is shown in FIG. The deoxidizing tower 11 contains CuO (80% by weight)-ZnO (20% by weight) prepared by the coprecipitation method described in Example 1.
2.5 liters of a binary composition catalyst consisting of: The upper parts of the adsorption towers 13 and 14 were each filled with 50 liters of petroleum-based pitch activated carbon having a most frequent pore diameter of 17 Å, and the lower parts were each filled with 20 liters of commercially available activated alumina. Among these adsorbents, activated carbon may be further mixed with activated alumina and/or activated zeolite. Introducing an inlet gas amount of 25.0Nm ³ /hr, deoxidizing tower 1
1 was maintained at 100° C., and adsorption (PSA) columns 13 and 14 were operated in a 5-minute cycle. These results are shown in Table 2.

[Table] In this way, it can be seen that impurities such as carbon dioxide, oxygen, hydrogen sulfide, and water, which are harmful to organic synthesis, can be sufficiently removed by treating the actual gas in only two steps in this example. Nitrogen and hydrogen remain, but there is no problem with organic synthesis using carbon monoxide. In addition, for the above-mentioned eighth embodiment, CuO was used as a catalyst.
In the comparative example using a single catalyst or a single ZnO catalyst, 0.5 vol% of oxygen gas remained in the product after the second step;
It was impossible to use this as a raw material gas for carbon monoxide in organic synthesis.

[Brief explanation of the drawing]

FIG. 1 is a flow diagram showing an example of the PSA method in the second step of the present invention, and FIG. 2 is a diagram showing the relationship between O ₂ removal rate and catalyst bed temperature according to the method of the present invention.
Figure 3 is a diagram showing the relationship between O ₂ removal rate and catalyst usage time, Figure 4 is a diagram showing the relationship between O ₂ removal rate and catalyst composition, and Figure 5 is a diagram showing the relationship between O 2 removal rate and catalyst composition. A series of flowcharts of the two steps, FIG. 6 shows a timing chart of opening and closing of the electric valve, and FIG. 7 shows a state diagram of the adsorption tower at that time. 1A, 1B, 13, 14...Adsorption tower, 2a, 2
b...Adsorbent, 3...Purified gas tank, 4...Material gas introduction piping, 5...Purified gas outlet piping, 6...
…Purified gas piping for cleaning, 7…Piping, 8…Gas purge piping, F ₁ to _{F 4} …Gas flow meter, V ₁ to V ₁ …
...Switching valve, 10...Gas flow path, 11...Deoxygenation tower.

Claims (1)

[Claims] 1. By bringing a raw material gas for synthesis containing carbon monoxide and impurities into contact with a binary composition catalyst that combines partially reduced copper oxide and zinc oxide, oxygen in the impurities is removed. A first step of reacting with carbon monoxide to convert it into carbon dioxide, and using the raw material gas that has passed through the first step under pressure with activated carbon or a composition in which the activated carbon is mixed with zeolite and/or activated alumina. A method for purifying carbon monoxide gas for synthesis, comprising a second step of adsorbing and removing impurities by passing the gas through an adsorption column filled with an adsorbent. 2. The method for purifying carbon monoxide gas for synthesis according to claim 1, wherein the first step is carried out either under normal pressure or under increased pressure. 3. The synthetic material according to claim 1 or 2, wherein the adsorbent is made of activated carbon having a most frequent pore size of 14 to 30 Å, or a composition in which the activated carbon is mixed with zeolite and/or activated alumina. Method for purifying carbon oxide gas.